A = {1,2,3} ; B = {3,4,5} ; C = {1,5,6}
a) A ∩ B = {3}
b) A - C = {2,3}
c) C - A = {5,6}
d) (B∩C) - (A∩B) = {5,1}
e) (B∩C) ∪ (A∩B) = {5,3}
f) (B-C) ∪ (A-B) = {1,2,3,4}
